A properly insulated chimney is a key component of an energy efficient building. Effective insulation also contributes to the safe operation of the chimney. Unfortunately, chimney insulation has never been a top priority for builders, so you may need to install an insulated chimney in your chimney to make your system safe and efficient.
Many homes and commercial buildings are designed with a chimney on the outside wall. Modern prefabricated fireplaces with metal chimneys are usually sufficiently insulated between the outside of the chimney and the chimney. However, the old masonry is not isolated. Brick and mortar chimney tiles with clay tiles for chimneys offer very little thermal resistance, so the chimney on the outer wall draws heat out of the building, even if the chimney damper is closed.
The chimney that rises inside the building is exclusively isolated, being inside the structure, to the point that it protrudes from the roof. Such a chimney construction has a smaller negative impact on the energy efficiency of a building than a chimney on an external wall, but this can cause problems with a creosote. The presence of the upper part of the chimney, subjected to cold air, will cause the combustion products to condense inside the chimney near the top, which will lead to dangerous building creosote. A cold chimney above the bottom of a warm chimney also leads to downward flows, obstructing the lighting of the lights and the entry of smoke into the building.
If your chimney is not insulated, the simplest and economical solution for you is to install a metal chimney inside an existing chimney. You can wrap the liner with fire resistant insulation before inserting it into the chimney, or install a gasket first, and then pour the insulation material into the space between the liner and the inner walls of the chimney. Make sure that the liner you choose is large enough in the cross section for your fireplace and made of the right material for your application. Stainless steel should be used to burn wood, oil or coal, as well as high-performance appliances, while aluminum may be sufficient for low-efficiency applications.
You should immediately see the benefits of your newly insulated chimney. Fires will become easier and your wood will burn cleaner. Combustion products will remain hot all the way to your home, and not cool as they grow and condense to form creosote and soot inside your chimney. Your room should feel warmer, even if you do not burn fire, especially if you have a top damper that is closed above your chimney. Your annual chimney sweeping job will also be easier. You will have not only the accumulation of creosote, but also a cylindrical chimney is easier to clean than a square chimney.
Retrofitting your chimney with an insulated chimney is a relative small investment that will pay for itself over time. You will use less fuel, have a more comfortable home and will easily feel that your smoke system is safe and efficient.
